Material lift system



Sept. 1, 1970 w SMITH ET AL v 3,526,436

MATERIAL LIFT SYSTEM Filed June 11, 1968 2 Sheets-Sheet 1 FlG.2. 57

1 I I I I I I z -54 I I j z I FIG. 5.

i x l I-2 j 4 7 i I I I x I l i K 'WITNESSES INVENTORS Melvn W. Smth and Charles S. Kluth BY V % I I) ATT' Sept. l, 1970 M& w. SMITH ET AL 5 5 MATERIAL LIFT SYSTEM Filed June ll, 1968 2 Sheets-Sheet 2 ?I COMPRESSOR ---b COMPRESSED 4 eej AIR 24 57 59 65 54 60 'ro RECEIVER 53 L TO RECEIVER 50 FIG.4.

24 FROM COLLECTOR %COMPRESSED AIR E' United States Patent O U.S. Cl. 302-14 8 Clams ABSTRACT OF THE DISCLOSURE An air lift for an underwater mining system wherein aggregates collected by a bottom collector are propelled through a conduit to a surface vessel by means of an air injection system wherein an air pipe supplying compressed air is Situated within the conduit carrying the aggregates. The compressed air pipe is disposed within the conduit to maximize clearance between the air pipe and conduit. Connected to the bottom opening of the compressed air pipe is a member containing a pl-urality of small apertures behind which is a rotating turbine operable by air pressure. A tool means is connected to the end of the compressed air pipe and rotatable with the turbine to remedy any possible clogging of the conduit.

BACKGROUND OF THE INVENTION Field of the invention This invention in general relates to a lift system for fluid or solid materials, and particularly to an air lift system having great utility in the underwater mining field.

Description of the prior art Material lift systems are utilized in various Operations one example of which is underwater mining systems wherein a collector means rides along the sea 'bottom and is connected to a surface vessel by means of a conduit which serves to transport the collected aggregates to the surface vessel. The lifting of the collected aggregates to the surface vessel may be accomplished by means of a pump, however, various Operations employ an air lift.

In an air lift system a compressed air pipe external to the conduit is connected to the conduit at some point intermediate the ship and the collecting means. The air bubbles entering the conduit lessens the density of the fluid therein which then causes a movement up the conduit to effect a lifting action whereby collected aggregates at the collector means are propelled to the surface vessel. Where mining Operations are carried out at, for example 15,000 feet, it is required that many thousands of feet of compressed air pipe 'be utilized. The compressed air pipe significantly increases the drag resistance.

Therefore one object of the present invention is to provide an air lift system wherein the drag is significantly reduced.

In the prior art systems if a leak developed in the compressed air pipe there was a possibility of a complete shut-down of mining operations until a repair was made. This of course represents not only a time consuming but a very expensive operation.

It is therefore another object of the present invention to provide an air lift system whereby mining `Operations may still be carried out even if certain leaks develop in the compressed air pipe.

In prior art mining systems if the points of air injection into the conduit is to be varied it is necessary to halt the mining Operations, take up the conduit, and make the adjustment accordingly, again representing a time consuming and expensive operation.

Another object of the present invention therefore is to 3,5Z6,436 Patented Sept. 1, 1970 provide an air lift system wherein the point of air injection can be readily varied without the need for taking in conduit.

In prior art air lift systems possible clogging of the conduit due to collected aggregates represent a potential shutdown of mining Operations.

Accordingly, it is another object to provide an air lift system in which unclogging Operations may readily be carried out.

SUMMARY OF THE INVENTION The system for lifting desired material according to the present invention includes a first conduit means for transporting the collected material and extending 'between first and second vertically spaced points, the first conduit means including, or being immersed in, a fluid. A` second conduit means is disposed within the first conduit means and includes a discharge portion at the lower end thereof while at the upper end thereof means are provided for supplying the second conduit with a fluid such as compressed gas for introduction of that fluid into the first conduit means.

The discharge end of the second conduit is provided with means to introduce small air bubbles into the first conduit means to insure for higher efliciency of the air lift system.

The term material herein is meant to include not only solids but also fluids.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l serves to illustrate the various Components of an underwater mining system;

FIG. 2 is a view of the material lift conduit illustrating the lower portion of a compressed air conduit disposed therein;

FIG. 3 is a side elevational View, with portions broken away illustrating a portion of the vessel of FIG. 1;

FIG. 4 is a view along line IV-IV of FIG. 3; and

FIG. 5 is a View along line V-V -of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. l, there is illustrated by way of example a typical mining system including a surface vessel 10 which travels through the water in the direction of the arrow. Depending from, and towed by, the surface vessel 10 is a conduit means 12 connected to a collecting means 14 which travels on the sea .bottom 16. In order to accommodate for varying terrain, the collecting means 14 is connected to the conduit means 12 by flexible conduit 19 and ball or swivel joint 20.

In order to convey the collected aggregates or other material from the collecting means 14 to the surface vessel 10 through the conduit means 12 compressed air is introduced int-o the conduit means 12 at a point I intermediate first and second vertically displaced points, that is intermediate surface vessel 10 and the collecting means 14.

FIG. 2 is an enlarged view with parts broken away, of the conduit 12 at the injection point I illustrating the second conduit means in the form of compressed air pipe 24 disposed within the conduit 12. Air pipe 2 4 is provided with a disoharge portion at the lower end thereof for introducing compressed air into the conduit 12 to eifect lifting action. Air under pressure emerging from the air pipe 24 forms bubbles which rise through the column and water in the conduit 12, thus making that column of water less dense. The column of water tends to rise towards the surface, which action draws up the water in the lower portion of the conduit 12 and accordingly the collected aggregate with it. Large air bubbles tend to rise more quickly, a situation known as slippage.

In order to reduce slippage and increase the efficiency of the air lift system, the present invention provides means for reducing the size of the air bubbles which emerge into the condut 12. This means may take the form of a cover member 28 threadedly engaged with the air pipe 24 at the lower end thereof and including a plurality of small apertures 30. The plurality of small apertures 30 aid in reducing the size of the air bubbles that Would normally be provided were the cover member 2 8 omitted.

In order to further insure that the discharging air bubbles are of small size there is provided internally of the cover member 28 a small turbine 32 having a plurality of vanes 34 which in response to the compressed air supplied, serve to rotate the turbine 32 and periodically block the eXiting of air from various apertures 30.

If a situation should develop whereby collected aggregates should block the condut 12, the present invention provides for unblocking the condut without the necessity for total cessation of rnining Operations and withdrawal of the condut from the water. Means whereby unclogging may be etfected include a blade 40 which is connected to, and rotated by, the turbine 32.. A feature of the present invention is that the air pipe 24 may be moved relative to the condut 12 internally thereof, and accordingly the air pipe 24 may be lowered to the point of clogging whereby the rotating blade 40 may remedy the situation.

Although compressed air is Conveniently used and supplied by air pipe 24, the material lift system herein can use other fluids, including gases, less dense than the fluid within the condut 12.

The positioning of the air pipe 24 within the condut 12 eliminates the drag resistance encountered in prior art types of air lift systems. In addition, with the present arrangement if an air leak should develop, the air will escape to the inside of the condut 12 whereby lifting action may be maintained, although at a possible reduction in efiiciency, whereas in prior art systems the compressed air would be lost to the surrounding water medium.

One means by which air pipe 24 may be inserted and operated within the condut 12, is illustrated in FIGS. 3, 4 and which reference is now made.

Many rnining vessels include a central well portion through which collector and condut are lowered. FIG. 3 therefore illustrates the surface vessel with a portion broken away showing a central well portion 43. In order to accommodate for pitch and roll of the vessel 10 during rnining Operations, the condut 12 passes through and is held by a gimbal 46, operative to rotate about first and second axes perpendicular to one another, such gimbals being well known to those skilled in the art. The gimbal 46 and condut 12 are illustrated in FIG. 3 in the position wherein the condut 12 is being towed. The upper portion of the condut 12 is joined to a deflector means for di recting the collected aggregates to a suitable receiving or storage means. One form of deflecting means which may be utilized herein is the deflector 47 shown in FIG. 4, FIG. 4 being a View along the line IV-IV of FIG. 3 with a portion of the gi'mbal 46 broken away.

The gimbal arrangement 46 includes a first frame member 48 rotatable about a first horizontal axis, and a second frame member 49 connected to frame member 48 and rotatable about a second horizontal axis in the same horizontal plane as, and perpendicular to, the first axis.

The lower condut section 50 of the deflector 47 includes a shoulder member 51, which in conjunction with slip or wedge means 52 secures deector 47 in the gimbal 46.

For vessel balance and equalization purposes it is preferable that a receiving means be located on the port and starboard side of the vessel. Accordingly, the deflector 47 is bifiurcated to include first and second arms in the form of curvilinear condut portions 53 and 54 connected through respective swivel or ball joints 56 and 57 to conduit sections 59 and 60, the latter two sections being connected with the starboard and port receivers respectively.

In accordance with the teachings herein, means are provided in order to insert the air pipe 24 into the condut 12. The means includes a funnel member 63 having wall portions tapering toward the lower condut section 50, and a base portion 64 Situated at the junction of curvilinear conduits 53 and 54 and forming at the junction an aperture 74 (see FIG. 5). Formed at the top of funnel 63 is a pipe holding portion 65 operable to hold the upper part of air pipe 24 which is connected to the compressor 68, or alternatively to any source of fluid less dense than the fluid in the condut '12. (The tapering of the funnel 63 insures that the air pipe 24 is directed to the aperture 74 for various angles of insertion.)

In order to maximize the area available within the condut 12 for aggregates being carried to the receivers, the air pipe 24 is preferably inserted in a manner that its central axes is not coincident with the central axis of condut 12. This feature may readly be seen by reference to FIG. 5 which is a view along line V-V of FIG. 4.

In FIG. 5, C represents the central axis of the condut 12 and C' represents the central axis of the air pipe 24. It is seen that the funnel 63 is located forwardly (with respect to the direction of travel of the vessel 10) of the central axis C and accordingly the air pipe 24, at the surface vessel, is inserted within the condut 12 forwardly of the central axis C and is held by the pipe holding portion 65 including slip or wedge means 71. In actual practice the air pipe 24 may be comprised of a plurality of sections each of which is inserted into the pipe holding portion 65, is held in place by the wedge means 71 until another section of air pipe is connected, is then lo wered one pipe length after removal of the wedge means 71 and the process repeated until the desired air pipe is payed out.

The air pipe insertion means including wedge means 71 facilitates the addition or removal of air pipe section so that the point of air injection (I FIG. 1) can be vared to accommodate for varying rnining depths and optimizing production rate with a given quantity of air. In addition, unclogging procedures may take place with the tool means illustrated in FIG. 2.

Although the present invention has been described with certain degree of particularity, it should *be understood that the present disclosure has been made by way of example and that modifications and variations of the present invention are made possible in the light of the above teachngs. Additionally, although the invention has been described in an underwater rnining environment, it will be appreciated that it is equally applicable to underwater or land systems involving the collection of fluid, such as oil, or land rnining systems wherein material in a flooded area is raised via a condut.

We claim as our invention:

1. A material lift system comprising:

(a) first condut means extending between first and second vertically spaced points for transporting collected material, and including a first fluid within said first condut means;

(b) second condut means disposed within said first condut means and including a discharge portion within said first condut means;

(c) means for supplying said second condut means with a second fluid less dense than said first fluid, for introduction of said second fluid into said first condut means; and

(d) said second condut means being movable relative to said first condut means for varying the location of said discharge portion with respect to said second point.

2. Apparatus according to claim 1 which additionally includes:

(a) rotatable tool means projecting exteriorly of the discharge portion and movable with the second condut means.

3. Apparatus according to claim 1 which additionally includes:

(a) deector means connected to the upper portion of the first conduit means whereby collected material may be directed to suitable receiver means.

4. A material lift system according to claim 1 for collection of material on the sea bottom, wherein:

(a) the first point is located on a surface vessel;

(b) the second point is located near the sea bottom,

(c) the first fluid is the ambient sea water; and

(d) the second fluid is a compressed gas.

5. Apparatus according to claim 4 which additionally includes:

(a) deector means connected to the upper portion of the first conduit means and including a lower conduit section and a bfurcated upper conduit section forming first and second arms.

6. Apparatus according to claim 5 which additionally includes:

(a) conduit insertion and holding means for the second conduit and positioned at the junction of the first and second arms and communicatve with the lower conduit section of the deflector means;

(b) said conduit insertion and holding means including wall portions tapering toward the lower conduit section of the defiector means.

7. Apparatus according to claim 6 Wherein:

(a) the surface vessel is adapted to travel through the water;

(b) the conduit insertion and holding means is positioned for inserting the secondconduit means forwardly with respect to travel of the surface vessel, of the central axis of the first conduit means.

8. A material lift system comprisng:

(a) first conduit means extending between first and second vertically spaced points for transporting collected material, and including a first fluid within said first conduit means;

(b) second conduit means dsposed within said first conduit means and including a discharge portion within said first condiut means having a pluralty of relatively small apertures;

(c) means for supplying said second conduit means with compressed gas, for introduction of said gas into said first conduit means;

(d) turbine means positioned at said discharge portion and rotatable by said compressed gas;

(e) said turbine means being positioned relative to said apertures to periodically block the exiting of said compressed gas from said apertures.

References Cited UNITED STATES PATENTS 661,609 11/1900 Hoover et al 302-15 1,042,189 10/ 1912 Beduwe 302-15 2,499,693 3/ 1950` Stanton 302-58 3,148,464 9/1964 Jones 302-15 ANDRES H. NIELSEN, Primary Examiner U.S. CI. X.R, o s 

